When you hit a guy in the private area with great force.
*guy gets a jack slap and falls on the floor in great pain*
by sabrina!! January 30, 2014
Get the jack slap mug.
To slap someone round the head for saying something in jack speak (naval language).
Sam says: "Can I go for a wash?"

LSA Swashbucket replies: "It's a dobey not a wash!"

SLAP!! Sam jack slap's LSA Swashbucket with force round the head.
by [FP]*PompeyPaul August 20, 2007
Get the jack slap mug.
Present tense for slapping someone so hard they don't know jack diddley

Jack-slapped; past or future tense for slapping someone so hard they don't know jack diddley
1. What if I jack-slap him

2. He just got jack-slapped by his girlfriend dude

3. That boy is gonna get jack-slapped
by Dacatoa May 23, 2018
Get the Jack-slap mug.
the act of defecating on a soft platter of sorts, such as a napkin or some paper towels, and holding the contraption while it lies open in the initiators hand. The user then proceeds to slap the victim in the face with the feces in his/her hand.
A: Dude i totally "Jack-Slapped" Steve in the face earlier!
B: Oh snap thats nasty!!!

C: Charlie, "Jack Slapping" Ms.Springs while pulling stick is unacceptable, especially during an exam.
D: Sorry Mom, I promise not to snap again.
by That_dude_down_the_street October 14, 2013
Get the Jack slapping mug.
(v.) The act of slapping someone across the head with your peins.
Bob: Yo I totally Jack Slapped Snayha last night!
MING-MING: But how she's so much taller than you?
Bob: I brought a step ,stool.
MING-MING; Nice.
Get the Jack Slapped mug.
(v.) The act of slapping someone across the head with your peins.
Bob: Yo I totally Jack Slapped Snayha last night!
MING-MING: But how she's so much taller than you?
Bob: I brought a step stool.
MING-MING; Nice.
Get the Jack Slapped mug.